Edwin t



(No Model.)

E. T. GREENFIELD.

METALLIC JUNCTION BOX AND MEANS FOR UNITING METAL UONDUIT TUBES THERETO.

UNTTED STATES PATENT rrrcn.

EDVIN T. GREENFIELD, OF NEV YORK, N. Y., ASSIGNOR TO THE INTRIOR CONDUITAND INSULATION COMPANY, OF SAME'PLACE.

METALLIC JUNCTION-BOX AND MEANS FUR UNITING METAL CONDUlT-TUBES THERETO.

SPECIFICATION forming part of Letters Patent No. 570,167, dated October27, 1896.

Application filed April 6, 1896. Serial No. 586,428. (No model.)

To @ZZ whom, it may concern:

Be it known that I, EDWIN T. GREENFIELD, a citizen of the United States,residing at New York, in the county of New York and State of New York,have made a new and useful lmprovementin Metallic J unction-Boxes andMeans for Uniting Metal Conduit Tubes Thereto, of whichthe following isa specilication.

My invention has for its objects, iirst, to increase the efiiciency ofjunction-boxes of the type named, and, second, to diminish the expenseof the structure of such boxes and their attachments.

My invention will be fully understood by referring to the accompanyingdrawings, in which Figure l represents in plan view the interior of anelectrical junction-box provided with my improved means for attachingthree radiating conduit-tubes thereto. Fig. 2 is a sectional view of thesame, taken on line ma, Fig. l. Fig. 2L is a detail perspective view ofone of the split locking-rings for locking the parts together, and Fig.3 is a longitudinal sectional view illustrating` the application of myimproved means of uniting conduit-tubes to j unction-boxes as applied tothe joining together of a pair of conduittubes.

Prior to my invention it was old in the art to make metallic junction-boxes provided with tubular necks adapted to receive interiorlythe ends of tubular conduits. It has been customary in the use of suchjunction-boxes to unite such tubular conduits thereto in various ways,but not, however, with such security as would prevent them from beingdrawn out of the necks under undue strain. lt is true that such a unionmight be effected by providing female screwthreads for the innersurfaces of the projecting necks of such boxes and corresponding malescrew-threads upon the outer surfaces of the ends of the conduit-tubes;but such methods of union have heretofore been rejected owing to theexpense of screw-threading the parts. It was with a view of providing ameans of uniting these parts securely together in a cheapA and efficientmanner that my present invention was devised, and

I will now proceed to describe the same, referrin g to the drawings indetail. n

I cast junction-boxes B of soft metal in molds, under air-pressure, in amanner well understood by those skilled in metal working, saidjunction-boxes being provided with any desired number of necks N N N,cast integral with the boxes and screw-threaded on their outer sufaces,the screw-threads be- 6o ing formed, preferably, during the process ofcasting. These j unction-boxes are then lined with paper H, treated withinsulating material, or any preferred insulating-lining may be used andapplied in any manner by those skilled in the art.

F F represent lugs which are provided with screw-holes for securing thebox to the wall or ceiling.

C represents a detachable cap adapted to 7o be secured to the top of thebox by screws s or in any preferred manner.

T T T represent armored conduit-tubes provided with insulating-liningsP, the ends of said tubes being adapted to iit snugly Within the innersurfaces of the necks N N N.

R represents a split ring of metal adapted to fit snugly upon the outersurface of the tubes T, said split ring being cone-shaped at one end andadapted to iit in the correspond- 8o ing cone-shaped outer ends of thenecks N N N.

D represents a screw-threaded locking-collar which is adapted to iitover the ends of the tubes T so that its inner surface will abut againstthe base of the split ring R, said locking-collar, with itsscrew-threads, being cast under pressure in the same manner as was thebox B.

E represents a iianged thimble of insulat- 9o ing material adapted tofit in the inner end of the neck N so that its free end extends into thejunctionbox slightly beyond the insulating-lining H thereof.

In uniting the parts together the thimbles E are inserted in the mannershown in Fig. 2 into the necks N of the ju notion-box, and the ends ofthe tubes T are inserted against the anged ends of said thimbles, thelockingcollars D and rings R having first been slipped 1 oo upon saidtubes. The locking-collars are then turned through the agency of apipewrench into locking position, the screwthreads t on the colla-rs i'and the corresponding screw-threads in the locking-collars causing thewedge-shaped rin to vforce the tubes T lirmlyhomc against the llan gesof the thimbles IC. \Vith such an arrangement the wedge action et' therings R causes the inner ends of the tubes T to be as iirmly united tothe junction-boxes as would be possible with screwthreads. In place ofthe rings R, I might use simple wedges disposed at various peints aroundthe tubes T.

In Fig. 3 I have shown the application of my ilnproved lockingmeans foruniting two armored tubes T T together through the agency of alocking-joint G and the lockingeollars I) D and locking-rings R R, E Illbeing insulating gaskets or rings adapted to complete the insulationbetween the insulating-lining IJ I et' the tubes and the correspondinginsulating-lining of the locking joint G.

My claims hereinafter made are designed to cover also the application ofthis `feature to uniting pipes or tubes together, as well as to theunion ot tubes to junctiouboxcs- This invention also has equal utilityin connection with concentric systems of conductors in which the outertube T and the junction-box ll constitute a part et the electricalconducting system.

In the event ot' the use ot' my invention with concentric systems ofconductors the outer ends ol.' the tubes T and the inner surlaees ot'the integral necks N should be pretera-bl y electroplated with copper,and the split ring R should be ot' copper or other goed conductingmetal. I should prefer also to have the locking-collar D in thateventot' copper, for the purpose oi' increasing the conductivity ot' thesystem. \\'hen used in connection with concentric systems, the lining IIand thimbles E might, il;l preferred, be done away with, the interior orconcentric conductor being a \\ellinsulated conductor.

Having thus described my invention, what I claim, and desire to secureby .Letters latent of the United States, is-

l. A junction-box provided with an integral screw-threaded neck, ascrew-threz'ided locking-collar and means for lirmly gripping or holdinga tube in place in alinement with said neck, said gripping means beingadapted to exert a wedgiug action between the neck and thelocking-collar, substantially as dcscribed.

2. A junction-box provided with an integral screw-threaded neek,in combination wi th a tube adapted to tit snugly within said neck, and aceneshaped ring for gripping or holding the tube and the neck i'lrmlytogether, substantially as described.

A j auction-box provided with a series of integral screw-threaded necks,a series el.' tubes adapted to lit each snugly within one oi said necks,and a locking-collar and wedg ing means foreach neck adapted to unitesaid neck and tube together, substantially as described.

4c. A junction-box provided with one or more eXteriorly-screw-thrcadednecks,in eombination with a screw-threaded locking-collar and acone-shaped split .ring Vfor grasping or holding' a pipe or tube inalinemcnt with said neck, substantially as described.

5. A metallic junction-box provided with an insulating-lining and aseries et' hollow screw-threaded necks, an insulating-thimble for eachneck extending within the box, an armored com'luit-tube adapted to litwithin each neck, a screw-threaded locking-collar foreach neck, and alocking d evice controlled thereby, all of said parts being so arrangedthat when the collars are screwed home the parts are rigidly unitedtogether, substantially as described.

In testimony whereof I have hereunto subscribed my name this l-th dayof; April, 1896.

ICD'WIN T. GREENFIICLD.

Witnesses:

C. J. KINTNEH, W. T. RUETE.

